One Minute Paper Statics; reply
Fluid dynamics Fluids in motion Pumps Fans Compressors Turbines Heat exchangers
Conservation Energy & mass; neither created nor destroyed in ordinary process Control volume Steady state: no accumulation nor depletion
Flowing fluid Steady flow Uniform flow Mass flow rate: Kg/ time, lbm/time Volume flow rate: m 3 /time, ft 3 /time, cfm, gpm
Continuity Mass flow rate Volume flow rate
Nozzle (ρVA) 1 = (ρVA) 2
Energy balance Kinetic Potential Flow Energy – changes in properties
Bernoulli Equation Energy per weight of flowing fluid Head Pressure Velocity Elevation
Bernoulli Equation Assumptions Steady state Incompressible fluid No friction in fluid stream
Bernoulli Equation Useful because: Process flow reasonable steady Compressibility effects small Friction effects minor
Example Water flowing from hose attached to a main at 400kPa. Boy covers most of hose outlet with thumb, producing a vertical, thin jet of high speed water. What is maximum height of jet?
Example A large tank open to the atmosphere is filled with water. A tap near the bottom of the tank is opened to allow flow from a smooth, rounded opening. Find the outlet velocity.
Example During a trip, motorist runs out of fuel. A helpful driver allows you to siphon fuel from her auto. (2) is located 0.75m below (1); (3) is 2m above (1). Siphon diameter is 4mm. Find the minimum time to transfer 4 L of fuel & the pressure at (3). Fuel density is 750 kg/m 3.
Homework Water flows through a 2-inch diameter pipe at 200 lbm/min. Its temperature is 60 o F. Find the velocity of water flow.
Homework Water from a pipe line is diverted into weigh tank for exactly 9 minutes. Tank weight increases 4765 lbf. Water temperature is 60 o F.
Homework Steady flow of gas through a pipe whose diameter decreases from 1.0 meter to 60cm. The gas density decreases from 2 kg/m 3 to 1.6 kg/m 3. The entering velocity is 25 m/s. What is exit velocity?
References Images & examples Mechanics of Fluids, 3rd Edition, Potter & Wiggert, Brooks & Cole Applied Fluid Mechanics, 6 th Edition, Mott, Prentice Hall Engineering Fluid Mechanics, 5 th Edition Crowe, & Roberson, Wiley Fluid Mechanics Cengel & Cimbala McGraw Hill Which of the examples were helpful?